Grevillea robusta Proteaceae

Eastern Australia

Am: Grevila; Eng: Silky oak, Grevillea

Ecology Each capsule contains only two seeds that A very successful Australian tree planted are dispersed by wind soon after the capsule and widely used in Africa, 0–3,000 m. splits open. Capsules can be collected Grows on fairly well drained and neutral when they are brown and mature but to acidic soils but does not tolerate water just before they split and then be kept for logging or heavy clays. In Ethiopia, it does drying, splitting and extraction of seeds. well in Dry, Moist and Wet Weyna Dega Germination rate 30–90 %. 70,000– and Dega agroclimatic zones, 1,500–2,700 110,000 seed per kg. m. Treatment: Not necessary for fresh seed.

Uses Storage: Seed can be stored for up to Firewood, charcoal, timber (furniture), three months, but this period can be poles, fodder (leaves), bee forage, shade, extended if it is refrigerated. It is better ornamental, soil conservation, windbreak. to avoid storage.

Description Management A semi‑deciduous tree to 20 m or more Moderate to fast growing. Pollarding, with a straight trunk and angular branches. lopping, coppicing and pruning. Only An oval leafy crown. BARK: Dark grey, young trees coppice well. rough, vertically grooved. LEAVES: Remarks Compound, fern‑like, very divided, It can be an important dry-season fodder leathery pale green above, silver‑grey below. although not top-quality. The leaf litter can FLOWERS: Very many, in one‑sided be used as bedding material in livestock golden‑orange spikes, much nectar which zero-grazing units. A mixture of manure attracts bees and sunbirds. FRUIT: Dark and Grevillea leaves make a very good brown capsule, about 1 cm, with a slender addition to the soil. The tree grows well beak, splitting to set free 2 winged seeds. with food crops if managed to reduce shade. Propagation The timber is hard and has an attractive Wildings, seedlings. grain — the red-brown colour and silky surface like that of the true oak, Quercus. Seed The species is a prolific seeder. Collection of large amounts of seed is time consuming.

290 | Useful Trees and Shrubs of Ethiopia Photo: Patrick Maundu Photos: Patrick Maundu

The Species | 291